It says in the blog that they require 13,000 queries per second to update lease objects, not that 13,000 is the total for all queries. I don't know why they cite that instead of total, but etcd's normal performance testing indicates it can handle at least 50,000 writes per second and 180,000 reads: https://etcd.io/docs/v3.6/op-guide/performance/. So, without them saying what the real number is, I'm going to guess their reads and writes outside of lease updates are at least much larger than those numbers.